1. Field of the Invention
This invention relates to pattern recognition systems and particularly to a system for enhancing two-dimensional binary data.
2. Decription of the Prior Art
In the prior art different enhancement techniques have been employed to enhance two-dimensional pattern images for pattern recognition applications.
One enhancement technique is a complex subsystem that is integrally a part of a complex pattern recognition digital computer, as taught in U.S. Pat. No. 3,581,281. In this pattern recognition computer, a sensed image is digitally stored in a matrix of memory elements which are selectively addressed. The values of the addressed memory elements are stored and summed in an accumulator. Signals from the accumulator above a predetermined threshold are distributed for further signal accumulation and thresholding before output signals are derived and supplied to indicators.
Another proposed character recognition system is the IBM 1975 Optical Page Reader which utilizes equipment to recognize more than 200 type fonts of characters, with part of that equipment employing an adaptive process to enhance the gray level data by converting it to binary data and then simplifying this binary data in a complex processing manner. Descriptions of parts of this proposed system can be found in the published articles on "The IBM 1975 Optical Page Reader," Parts I, II and III, contained in IBM J. Res. Develop. 12, No. 5, pages 346-371 (September 1968). Part II (pages 354-363) includes a discussion related to the enhancement of character data. The enhancement technique disclosed in Part II relies on a relatively complex hybrid of analog and digital processing.
Other proposed systems utilize circular scanning techniques to derive redundant binary information. Any enhancement of the resultant binary information is directed essentially to removing or minimizing the redundancy rather than an actual enhancement of the pattern image.
In all of the above known equipments, complex circuitry and processing is required for enhancing the two-dimensional binary data derived from sensing a pattern image. In addition, in some of these prior art systems, the enhancement technique does not result in a high degree of enhancement of the two-dimensional binary data. None of these proposed systems teach an essentially simple structure which can achieve a high degree of enhancement of two-dimensional binary data.